vania and Eighth Illinois Regiments, and Barker's squadron of cavalry, the whole composing the advance guard of the Army of the Potomac. My instructions were to pursue and harass the rear of the retreating enemy, and if possible to cut off his rear guard, or that portion of it which had taken the Lee's Mill and Yorktown road. In harassing the enemy I was to be supported by Hooker's division, which was to follow us by a forced march along the Yorktown and Williamsburg road, and in cutting off the rear guard I was to co-operate with the division of General Smith, which was to march on the other, or Lee's Mill, road. Six miles from Yorktown we came upon the enemy's pickets. Two miles farther we came up with the rear of his rear guard, consisting of a regiment of cavalry, with a deep ravine and bad crossing between us and him. From this position he was driven by Gibson's battery. Here I sent General Emory, with Benson's battery and the Third Pennsylvania Cavalry and Barker's squadron, across to the Lee's Mill road to cut off any force on that road and between Emory's and Smith's column, advancing as was supposed along that road, and with the remainder I pushed on as fast as safety would permit to occupy the junction of the road from Yorktown with that of Lee's Mill, 2 miles from Williamsburg.

Here I will state that previous to sending Emory across I had communicated with the advance guard of Smith's column, and had heard, through one of my aides, that Hooker was close behind us with supporting divisions. General Cooke, commanding the advance, consisting of a section of Gibson's battery and a portion of the First Cavalry, upon debouching from the woods found himself at the junction of the two roads and in front of a strong earthwork flanked by redoubts, and in the presence of a strong rear guard of the enemy, consisting of a regiment of cavalry, a battery of artillery, and three regiments of infantry. General Cooke immediately made dispositions to attack the enemy with the small force at this disposal, and I hurried up the remainder of the First Cavalry and Gibson's battery. Owing to the limited space of cleared ground in which we could possibly operate with cavalry or artillery, I was unable to bring into action more than one battery and about 300 cavalry. The remainder of the force I directed formed in a clearing half a mile to our rear to cover our retreat, which I saw must necessarily soon be made unless the infantry support, 2 miles behind at last accounts, should come to our assistance.

After great exertion, rendered necessary by deep mud and thick abatis, Captain Gibson got his battery to play upon the enemy, and Colonel Grier put his regiment in position to support it. In the meantime the enemy, strongly re-enforced from his main body, had thrown himself behind the abandoned earthwork, and several regiments of infantry were seen marching in a direction indicating their intention to turn our right and cut us off. I directed Major Williams, with a portion of the Sixth Cavalry, to make a demonstration through the woods on our right, with the view of holding the enemy in check until the arrival of our infantry support, which I had sent Governor Sprague bank to hurry up. The firing from Fort Magruder in front of the First Cavalry and Gibson's battery was producing great effect upon both men and horses; the Sixth Cavalry had come upon a strong force of infantry and cavalry, and was secured from disaster by a gallant charge made by the rear squadron, commanded by Captain Sanders, during the withdrawal of the regiment. The First Cavalry had made two brilliant charges, and horses and men were falling at their guns. The enemy was receiving re-enforcements every minute. After holding our